1. Field of the Invention
The invention relates to a detection system for recognizing the approach of a hand or arm movement in a direction towards a display and operating unit, detection being carried out in two stages.
2. Related Art
Proximity and touch sensors are being used more and more often in the interior of vehicles to optimize interaction between a user and an information and assistance system in a user-friendly manner. In this case, gestures or approaches are detected and analyzed. This is effected by generating a physical measurement variable and converting the physical measured variable into an electrical signal. An action is then triggered using a control device.
To support interaction between a user and an information system, a few systems are known that detect when a display or an operating element is approached and/or allow the driver and passenger to be differentiated. The display and operating concept is then changed in a manner adapted to the context based on the detection result. Approach detection apparatuses are cited in a few documents.
The document WO 2007/006514 A1 discloses an approach detection apparatus having a transmitting and receiving unit. In this case, the apparatus operates optoelectronically in an area outside the vehicle. When a person approaches from a predetermined, central direction, a control signal is triggered in a close range of the vehicle using a code transmitter carried by the person.
Detection in known apparatuses is carried out in a defined detection range in the close range of a display or an operating unit. Signals are permanently injected into the user by using capacitive sensors.
The known apparatuses and methods have the disadvantage that the user must carry a transmitting unit or a code transmitter, in the form of a chip card, or a transmitting unit integrated in the car key in order to trigger a control signal. Furthermore, a large amount of energy is required as a result of signals being permanently injected into the human body. Detection devices may be perceived to be harmful to health by the user as a result of the permanent signal injection, that is to say as a result of the user being exposed to magnetic and/or electric fields.